title: Study on the observation of Eu2+ and Eu3+ valence states in low silica calcium aluminosilicate glasses.
abstract: The optical, magnetic and structural properties of Eu doped low silica calcium aluminosilicate glasses were investigated. The optical absorption coefficient presented two bands at 39,246 and 29,416 cm(-1), which were assigned respectively to the [Formula in text], and [Formula in text] transitions of Eu(2+). The fluorescence measured at 300 K on a sample doped with 0.5 wt% of Eu(2)O(3) exhibited a broad band centered at 17,350 cm(-1), which is attributed to the [Formula in text] transition of Eu(2+), whereas the additional peaks are due to the [Formula in text] transitions of Eu(3+). From magnetization and XANES data it was possible to evaluate the fractions of Eu(2+) and Eu(3+) for the sample doped with 0.5 and 5.0 wt% of Eu(2)O(3), the values of which were approximately 30 and 70%, respectively.
authors.affiliation: Laboratório de Ciências Físicas, Universidade Estadual do Norte Fluminense, Avenida Alberto Lamego 2000, CEP 28013-600, Campos dos Goytacazes, RJ, Brazil. jsampaio@uenf.br
authors.forename: J A
authors.initials: JA
authors.lastname: Sampaio
authors.forename: M C
authors.initials: MC
authors.lastname: Filadelpho
authors.forename: A A
authors.initials: AA
authors.lastname: Andrade
authors.forename: J H
authors.initials: JH
authors.lastname: Rohling
authors.forename: A N
authors.initials: AN
authors.lastname: Medina
authors.forename: A C
authors.initials: AC
authors.lastname: Bento
authors.forename: L M
authors.initials: LM
authors.lastname: da Silva
authors.forename: F C G
authors.initials: FC
authors.lastname: Gandra
authors.forename: L A O
authors.initials: LA
authors.lastname: Nunes
authors.forename: M L
authors.initials: ML
authors.lastname: Baesso